In musl libc through 1.2.1, wcsnrtombs mishandles particular combinations of destination buffer size and source character limit, as demonstrated by an invalid write access (buffer overflow).

The remote Ubuntu 16.04 ESM / 18.04 ESM / 20.04 ESM host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-5990-1 advisory.

    It was discovered that musl did not handle certain i386 math functions properly. An attacker could use     this vulnerability to cause a denial of service (crash) or possibly execute arbitrary code. This issue     only affected Ubuntu 14.04 ESM, Ubuntu 16.04 ESM, and Ubuntu 18.04 LTS. (CVE-2019-14697)

    It was discovered that musl did not handle wide-character conversion properly. A remote attacker could use     this vulnerability to cause resource consumption (infinite loop), denial of service, or possibly execute     arbitrary code. This issue only affected Ubuntu 14.04 ESM, Ubuntu 16.04 ESM, Ubuntu 18.04 LTS, and Ubuntu     20.04 LTS. (CVE-2020-28928)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The wcsnrtombs function in all musl libc versions up through 1.2.1 has been found to have multiple bugs in handling of destination buffer size when limiting the input character count, which can lead to infinite loop with no forward progress (no overflow) or writing past the end of the destination buffers.

For Debian 9 stretch, this problem has been fixed in version 1.1.16-3+deb9u1.

We recommend that you upgrade your musl packages.

For the detailed security status of musl please refer to its security tracker page at: https://security-tracker.debian.org/tracker/musl

NOTE: Tenable Network Security has extracted the preceding description block directly from the DLA security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

ID	Name	Product	Family	Severity
173730	Ubuntu 16.04 ESM / 18.04 ESM / 20.04 ESM : musl vulnerabilities (USN-5990-1)	Nessus	Ubuntu Local Security Checks	critical
143388	Debian DLA-2474-1 : musl security update	Nessus	Debian Local Security Checks	medium

Detections

Analytics

CVE-2020-28928

medium

Tenable Plugins

critical

medium